Outlets
The term “outlet” herein denotes an electromechanical device, which facilitates easy, rapid connection and disconnection of external devices to and from wiring installed within a building. An outlet commonly has a fixed connection to the wiring, and permits the easy connection of external devices as desired, commonly by means of an integrated connector in a faceplate. The outlet is normally mechanically attached to, or mounted in, a wall. Non-limiting examples of common outlets include: telephone outlets for connecting telephones and related devices; CATV outlets for connecting television sets, VCR's, and the like; and electrical outlets for connecting power to electrical appliances. The term “wall” herein denotes any interior or exterior surface of a building, including, but not limited to, ceilings and floors, in addition to vertical walls.
LAN Environment
FIG. 1 shows a typical prior art LAN environment 10. Such a network commonly uses 10BaseT or 100BaseTX Ethernet IEEE802.3 interfaces and topology, and features a hub 11 as a concentrating device, into which all devices are connected. Devices are connected to the hub 11 by data connectors 14a, 14b, and 14c, which are housed within network outlets 15a, 15b, and 15c respectively. Connections to the hub 11 are via cables 13a, 13b, and 13c respectively. Data connectors 14a, 14b, and 14c may be, for example, type RJ-45 connectors; and cables 13a, 13b, and 13c may be, for example, Category 5 cabling. The data portion of network 10 uses data units (which may be computers) 7a, 7b, and 7c, which connect to network connectors 14a, 14b, and 14c via cables 16a, 16b, and 16c, respectively. A server 12 may also be connected to the hub 11, and can perform the external connection functionality, as well as other server functions as applied in the art.
Although FIG. 1 refers to the hub 11 as a concentrating device, it is to be understood that any type of device having multiple network interfaces and supporting a suitable connectivity can be used, non-limiting examples of which include shared hubs, switches (switched hubs), routers, and gateways. Hence, the term “hub” herein denotes any such device without limitation. Furthermore, network 10 can be any packet-based network, either in-building or distributed, such as a LAN or the Internet
The topology of network 10 as shown in FIG. 1 incurs various maintenance difficulties. The wiring from the hub 11 to the data unit 7a, for example, includes wire 13a, connector 14a and wire 16a. Because these conductors are continuous, there is no easy way to distinguish a break or short-circuit in wire 13a from a break or short-circuit in wire 16a, nor from a break or short-circuit in connector 14a. Troubleshooting such failures requires disconnecting cables and inserting dedicated test equipment or making elaborate and thorough substitutions of components that are known to be functional. Such procedures are complicated, labor-intensive, time-consuming, and expensive. Furthermore, in the common case of an outlet to which no data unit is connected, there is no simple way to test the continuity of wiring from the hub to the outlet. In addition, in many cases it is necessary to test the LAN from a remote place (such as via the Internet) in cases where it is not possible to attach testing equipment to non-connected outlets.
Discussion of network management and example of network management system are part of U.S. Pat. No. 5,812,750 to Dev et al.
Home Networking
Most existing offices and some of the newly built buildings facilitate the network structure of network 10. However, implementing such a network in existing buildings typically requires installation of new wiring infrastructure. Such installation of new wiring may be impractical, expensive and hassle-oriented. As a result, many technologies (referred to as “no new wires” technologies) have been proposed in order to facilitate a LAN in a building without adding new wiring. Some of these techniques use existing wiring used also for other purposes such as telephone, electricity, cable television, and so forth. Doing so offers the advantage of being able to install such systems and networks without the additional and often substantial cost of installing separate wiring within the building. In order to facilitate multiple use of wiring within a building, specialized outlets are sometimes installed, which allow access to the wiring for multiple purposes. An example of home networking over coaxial cables using outlets is described in WO 02/065229 published 22 Aug. 2002 entitled: ‘Cableran Networking over Coaxial Cables’ to Cohen et al.
The use of such wiring for additional purposes creates a need for ways of easily determining the condition of the wiring and obtaining this information remotely.
Home networking using existing telephone lines will be described as an example.
Definitions and Background
The term “telephony” herein denotes in general any kind of telephone service, including analog and digital service, such as Integrated Services Digital Network (ISDN).
Analog telephony, popularly known as “Plain Old Telephone Service” (“POTS”) has been in existence for over 100 years, and is well-designed and well-engineered for the transmission and switching of voice signals in the 3-4 KHz portion (or “band”) of the audio spectrum. The familiar POTS network supports real-time, low-latency, high-reliability, moderate-fidelity voice telephony, and is capable of establishing a session between two end-points, each using an analog telephone set.
The terms “telephone”, “telephone set”, and “telephone device” herein denote any apparatus, without limitation, which can connect to a Public Switch Telephone Network (“PSTN”), including apparatus for both analog and digital telephony, non-limiting examples of which are analog telephones, digital telephones, facsimile (“fax”) machines, automatic telephone answering machines, voice modems, and data modems.
The terms “data unit”, “computer” and “personal computer” (“PC”) as used herein include workstations and other data terminal equipment (DTE) with interfaces for connection to a local area network
In-home telephone service usually employs two or four wires, to which telephone sets are connected via telephone outlets.
Home Networking Over Telephone Lines.
FIG. 2 shows the wiring configuration of a prior-art telephone system including a network 20 for a residence or other building, wired with a telephone line 5, which has a single wire pair that connects to a junction-box 34, which in turn connects to a Public Switched Telephone Network (PSTN) 39 via a cable 33 (‘local loop’), terminating in a public switch 32, which establishes and enables telephony from one telephone to another. The term “high-frequency” herein denotes any frequency substantially above such analog telephony audio frequencies, such as that used for data. ISDN typically uses frequencies not exceeding 100 KHz (typically the energy is concentrated around 40 KHz). The term “telephone line” herein denotes electrically-conducting lines which are intended primarily for the carrying and distribution of analog telephony signals, and includes, but is not limited to, such electrically-conducting lines which may be pre-existing within a building and which may currently provide analog telephony service.
Junction box 34 separates the in-home circuitry from the PSTN and is used as a test facility for troubleshooting as well as for new wiring in the home. A plurality of telephones may connect to telephone lines 5 via a plurality of telephone outlets. Each outlet has a connector (often referred to as a “jack”), commonly being in the form of RJ-11 connectors in North-America. Each outlet may be connected to a telephone unit via a compatible “plug” connector that inserts into the jack.
Wiring 5 is usually based on a serial or “daisy-chained” topology, wherein the wiring is connected from one outlet to the next in a linear manner; but other topologies such as star, tree, or any arbitrary topology may also be used. Regardless of the topology, however, the telephone wiring system within a residence always uses wired media: two or four copper wires terminating in one or more outlets which provide direct access to these wires for connecting to telephone sets.
It is often desirable to use existing telephone wiring simultaneously for both telephony and data networking. In this way, establishing a new local area network in a home or other building is simplified, because there is no need to install additional wiring.
The concept of frequency domain/division multiplexing (FDM) is well-known in the art, and provides means of splitting the bandwidth carried by a wire into a low-frequency band capable of carrying an analog telephony signal and a high-frequency band capable of carrying data communication or other signals. Such a mechanism is described, for example, in U.S. Pat. No. 4,785,448 to Reichert et al. (hereinafter referred to as “Reichert”). Also widely used are xDSL systems, primarily Asymmetric Digital Subscriber Loop (ADSL) systems.
Examples of relevant prior-art in this field are the technology commonly known as HomePNA (Home Phoneline Networking Alliance), WO 99/12330 to Foley and as disclosed in U.S. Pat. No. 5,896,443 to Dichter (hereinafter referred to as “Dichter”). Dichter and others suggest a method and apparatus for applying a frequency domain/division multiplexing (FDM) technique for residential telephone wiring, enabling the simultaneous carrying of telephony and data communication signals. The available bandwidth over the wiring is split into a low-frequency band capable of carrying an analog telephony signal, and a high-frequency band capable of carrying data communication signals. In such a mechanism, telephony is not affected, while a data communication capability is provided over existing telephone wiring within a home.
In addition to illustrating a residential telephone system, FIG. 2 also shows the arrangement of a Dichter network. Network 20 serves both analog telephones and provides a local area network of data units. Data Terminal Equipment (DTE) units 7a, 7b, 7c and 7d are connected to the local area network via Data Communication Equipment (DCE) units 25a, 25b, 25c and 25d, respectively. Examples of Data Communication Equipment include, but are not limited to, modems, line drivers, line receivers, and transceivers (the term “transceiver” herein denotes a combined transmitter and receiver), which enables data communication over the high spectrum of telephone line 5. DCE units (‘phoneline modems’) 25a, 25b, 25c and 25d are respectively connected to high pass filters (HPF) 24a, 24b, 24c and 24d, which allow access to the high-frequency band carried by telephone line 5. In order to avoid interference to the data network caused by the telephones, low pass filters (LPF's) 23a, 23b, 23c and 23d are added to isolate the POTS carrying band, so that telephones 26a, 26b, 26c and 26d connects to telephone line 5 for providing PSTN. Furthermore, a low pass filter may also be connected to Junction Box 34 (not shown in the figure), in order to filter noise induced from or input to PSTN wiring 33.
WO 01/71980 published Sep. 27, 2001 entitled “Telephone Outlet and System for a Local Area Network Over Telephone Lines” in the name of the present inventor and assigned to the present assignee, describes the integration of DCE 25, HPF 24, and LPF 23 components into outlets 21 in order to reduce complexity, as shown in FIG. 2. This allows direct connection of telephone sets 6a, 6b, 6c, and 6d to outlets 21a, 21b, 21c, and 21d, respectively, via dedicated connectors (as is done in prior-art common telephone outlets), as well as direct and easy connection of data units 7a, 7b, 7c, and 7d to the respective outlets via dedicated jacks, as is usually done in LAN systems (as shown in FIG. 1).
The topology of network 20 as shown in FIG. 2 exhibits the maintenance difficulties previously discussed. The data flow from data unit 7a to data unit 7b, for example, is via wiring 16a, wiring 5b and wiring 16b, as well as connectors such as 22a and 22b. Having continuous data flow, there is no easy way to distinguish a short-circuit in wiring 16a from a short-circuit in wiring 16b, or from a short-circuit in wiring 5b, or from a short-circuit in any of the interim connectors. Similarly, a break in the wiring cannot be easily or remotely isolated to wiring 16a or wiring 16b. Troubleshooting any of the above failures can only be accomplished by trial and error and requires disconnecting cables 16a, 16b, 16c, and 16d, and inserting other data units to the outlets. If the failure, however, is in wiring 5c, more troubleshooting will be necessary, and can ultimately involve disconnecting the entire network. As noted above, this is a complicated, expensive, labor-intensive, and time-consuming effort. Furthermore, in the common case of an outlet into which no data units are connected, there is no simple way to test wiring continuity to the outlet. In addition, as explained in WO 99/03255 to Bell, in many cases it is required to test the LAN from a remote place (e.g. via the Internet), and no local presence is available to approach the disconnected outlets for attaching testers.
U.S. Pat. No. 4,787,082 entitled Data flow control arrangement for local area network (Delaney et al.) published Nov. 22, 1988 discloses a local data distribution network wherein a plurality of bi-directional data distribution busses are each connected to a bus master control circuit at a terminal end of the bus. Connected to each of the data distribution busses are a plurality of passive outlets to which intelligent connectors or stations may be connected. Each station has a unique address and is utilized for individually coupling data processing devices to the bus. A bus termination hub switching facility cooperates with the included group of bus master control circuits to interconnect data processing stations on the various busses. The bus termination hub facility includes bus monitoring, status polling and maintenance facilities. A faulty bus is disconnected if a fault is discovered during monitoring intervals. It remains disconnected until the fault is corrected.
JP 55132197A2 published Oct. 14, 1980 in the name of Sharp Corporation and entitled “Unit Controlling Electric Equipment Making Use of House Wiring” relates to the control of electrical equipment connected to house wiring. An address information signal is sent through a coupling unit from a transmission controller to house wiring. On the reception side, reception controllers receive the address information signal through coupling units inserted into sockets provided at respective positions of the house wiring. From one of controllers whose incorporated address information agrees with the received address information, answer information is sent back to the transmission side. On the transmission side, an operation command code is sent out upon receiving the answer information from the reception side so as to control electric equipment.
In both above prior art patents, passive outlets are used, hence there is no way to distinguish between a failure in the wiring into which the outlets are connected, and a failure in the wiring/equipment connected to the outlet.
There is thus a widely recognized need for, and it would be highly advantageous to have, a method and system for allowing remote diagnosis of LAN environment outlets without requiring local access to the network and without dismantling the network. This goal is met by the present invention.